Term consumption determinant Definition: One of the ceteris paribus factors held constant when the consumption line (or propensity-to-consume line) used in Keynesian economics is constructed. Some of the more important consumption determinants are interest rate, consumer confidence, wealth, taxes, and expectations. A change in any of the consumption determinants result in a shift of the consumption line and a change in autonomous consumption. This is just the sort of thing that triggers the multiplier effect. Any consumption determinant triggering shift of the consumption line is matched by an equal by opposite shift of the saving line.